Your helmet is most probably the most important safety element of any cyclist's outfit. Although we have a lot of fun on our Trail Angels rides and on our bikes in general; it goes without saying that at some point you are going to fall. Especially while mountain biking.
Modern helmets are most of the time equipped with the MIPS technology that allows for rotational head impact as explained in the video below.
Take a look at your helmet and make sure you are comfortable with its safety features which you can read up on from the manufacturer's website. For example go to https://www.specialized.com/za/en/ambush-w-angi/p/162034?color=251082-162034&searchText=60219-1322 to read about the Ambush helmet in the picture above.
Apart from making sure that your helmet is safe, inspect it regularly for small cracks and keep in mind that your helmet needs to be replaced every 3-5 years.
If you want to have a more detailed explanation of the MIPS technology, read this article:
Stay safe out there.